Flyback switcher for offline supplies
The STMicroelectronics VIPER20DIP-E is a monolithic offline flyback switcher from the VIPER™ series, integrating the PWM controller and a 620 V avalanche-rugged power MOSFET in a single 8-DIP through-hole package. Rated for 20 W of output power, it targets isolated AC-DC converter designs for consumer and industrial auxiliary supplies—think appliance control boards, smart meters, and industrial sensor power modules. The internal startup circuit fires up at 11 V, and the IC operates from an 8 V to 15 V supply rail, with switching frequency programmable up to 200 kHz to shrink the transformer size.
The 620 V breakdown voltage provides headroom for universal mains input with a reasonable derating margin. 20 W output is the practical ceiling in the 8-DIP package; pushing past it requires better thermal management or a higher-power member of the VIPER family. The integrated current limiting and over-temperature protection keep the die safe during overloads. Switching at up to 200 kHz lets you use a smaller transformer core, but at the cost of higher switching losses.
Obsolete—sourcing the VIPER20DIP-E today
New designs should not use this part. For existing BOM lines, independent distribution is the only channel.